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Date: Mon, 29 Dec 2008 22:20:20 +0100
From: Andre Albsmeier <Andre.Albsmeier@siemens.com>
To: freebsd-arch@freebsd.org
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Subject: Two drivers, one physical device: How to deal with that?
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Hello,

I have written a driver which attaches to the host bridge in
order to periodically read the appropriate registers and
inform the user about ECC errors (ECC-Monitor). No I have
run across a mainboard where the host bridge is already
taken by the agp driver. Of course, I can detach the agp
driver and attach myself and everything is working but
what is if someone does not want to loose the agp
functionality?

How does one deal with the case when two separate drivers
have to access the same device (the host bridge in my case)?

I assume, the correct way would be to join the AGP and
ECC functionality in one driver but maybe there are other
tricks I am not aware of?

Thanks,

	-Andre